Chinese Envoy Says Negotiations This Week Made Progress But Main Issues Unresolved

VIENNA—With one month to go until a July 20 deadline, the odds of a high-stakes nuclear deal between Iran and six major powers appeared finely balanced, with senior diplomats saying this week's talks had shown "progress" but warning that gaps may prove too wide to resolve.

After five days of discussions in Vienna, top Iranian and U.S. officials demanded major concessions from the other side and there was no pretense of any...